THE USE OF X-RAY-FLUORESCENCE TO DETECT LEAD CONTAMINATION OF CARPETED SURFACES

The recognition of the hazards to young children of low-level lead int oxication and the widespread distribution of lead in the urban environ ment have resulted in massive federal, state, and local lead awareness and abatement programs. Two of the most significant exposure routes o f lead to young children are the soils and dusts found within the chil d's home. Most state and federal lead abatement programs deal with lea d-based paint contamination but often do not address the issue of soft -surface contamination, such as that of carpets, furniture, and draper ies. Carpets can be a reservoir of contaminated soils and dusts; curre ntly, there exists no standard method to test carpeted surfaces for le ad contamination. This paper describes a study that uses X-ray fluores cence (XRF) to test carpeted surfaces for lead contamination. XRF tech nology is the standard technology used in lead-based paint testing and is known to be an accurate technique to test for lead in soils. This study uses a controlled laboratory atmosphere to evaluate this technol ogy; the objectives are to determine: (1) a lower limit of detection f or the instrument; and (2) whether soil loading levels can be differen tiated by XRF using trace elements also present in the soil. Results i ndicate that XRF can easily differentiate soil loading levels (g soil/ m2 carpet). The lower limit of detection of soil lead concentration on the carpet is a function of both soil lead concentration and soil loa ding; therefore, lead loading (mg Pb/m2) is a better indicator of dete ction limit than soil lead concentration. Lead loading detection level s from 108-258 mg Pb/m2 were obtained, as compared to a level of 10 00 0 mg/m2 (1 mg/cm2) for lead on painted surfaces as required by the Lea d-Based Paint Poisoning Prevention Act. XRF technology has the potenti al to be a fast; inexpensive screening technique for the evaluation of lead contamination on carpeted surfaces.